MSD Install While Keeping Orange Box?

No, i think you misunderstand me. I don't want to run both at once. I just would like to leave the orange box on the fender and be able swap a wire or two to switch over. I've always kept a spare orange box in the trunk in the past. Not sure I trust the msd without a backup plan in case it fails while I'm on the road.

Ive had the MSD 6a box and billet distributor in my car for over 10 years now. Originally with a 318, now with a 340. Fires up with the flick of the key.

I don't think you are going to have to worry about it failing.